Justification of Red List Category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over 10 years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in 10 years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The global population is suspected to number c.100,000-1,000,000 individuals (Ferguson-Lees and Christie 2001), while national population estimates include: c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in China; < c.100 breeding pairs, c.1,000-10,000 individuals on migration and c.50-1,000 wintering individuals in Taiwan; c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in Korea; c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in Japan and c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in Russia (Brazil 2009). A global population estimate of 100,000-1,000,000 individuals is roughly equivalent to 66,666 - 666,666 mature individuals.
The population is suspected to be declining due to forest loss across its range. Data from Global Forest Watch (2021) suggests that the rate of forest loss is likely to be <20% over three generations.
Behaviour Birds in the northern part of its range are migratory, arriving at breeding grounds in April and May and leaving again between August and October. Further south the species is sedentary (del Hoyo et al. 1994). It migrates by flapping as well as soaring, enabling it to cross expanses of water. Small groups generally form on migration, but otherwise the species is generally seen singly or in pairs (Ferguson-Lees and Christie 2001).
Habitat It inhabits woodland of various climatic types, preferring broad-leaved forests; it is recorded up to 1,800 m (del Hoyo et al. 1994).
Diet Bees and wasps (usually larvae) form the main part of its diet (del Hoyo et al. 1994).
Breeding site The nest is built in the fork of a tree (del Hoyo et al. 1994).
Management information The species requires forest, although not necessarily old growth: it has been recorded to move back into irrigated forest plantations in Pakistan (del Hoyo et al. 1994).
It is highly vulnerable to the effects of potential wind energy development (STRIX 2012). It is also threatened by forest loss across its range (Global Forest Watch 2021).
Conservation Actions Underway
This species is listed under CITES II.
Text account compilers
Ashpole, J, Butchart, S. & Ekstrom, J.
BirdLife International (2022) Species factsheet: Pernis ptilorhynchus. Downloaded from http://www.birdlife.org on 25/06/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 25/06/2022.